This invention relates to bioengineering systems, and in particular, to a magnetic navigation system for moving a device within the body of an animal such as a human being. The system is particularly useful within tracts, ducts or cavities such as the gastrointestinal (GI) tract.
Various diagnostic techniques are used for detection of tumors, ulcers, and other abnormal conditions in the body. These techniques include x-ray imaging, ultrasonic testing, MRI, endoscopy, sigmoidoscopy and colonoscopy. Recently, a camera-in-a-capsule device has been developed and reported, see U.S. Pat. No. 5,604,531, xe2x80x9cIn vivo video camera systemxe2x80x9d issued to Iddan et al. on Feb. 18, 1997 and U.S. Pat. No. 6,428,469, xe2x80x9cEnergy management of a video capsulexe2x80x9d issued to Iddan et al. on Aug. 6, 2002. Recent FDA approval (August, 2001) of an ingestible camera developed by Given Imaging Ltd. and tested at New York Mount Sinai Hospital received considerable news media attention. Such a device is schematically illustrated in FIGS. 1 and 2.
Referring to FIGS. 1 and 2, the ingestible camera 10 is a finger-tip sized capsule 11 containing a camera composed of lens 12, an image detector 13 and one or more light sources 14. A wireless transmitter 15 (including antenna) is provided for video signal transmission. The capsule also includes, batteries 16, and circuit chips (not shown). When a patient swallows the capsule, the natural muscular waves of the digestive tract propel it downward; and, as it goes down, the camera takes pictures of the small intestine wall for video transmission to detect tumors, ulcers, or causes of bleeding. This procedure permits the diagnosis of the small intestine, which is difficult to access by colonoscopy. For larger regions, such as the stomach or the large intestine, this type of non-guided camera tends to lose orientation and reliable imaging covering all surface areas is no longer be possible. It would be desirable if the position of the camera could be controlled so that no portion of the GI tract surface would be missed.
The most common therapy for treatment of GI tract problems with drugs is oral administration, rather than a concentrated application of the drugs directly on the affected area. Such a practice results in inefficient use of drugs, and is often accompanied by unwanted side-effects, with restrictions in the use of more potent treatment doses, especially in the treatment of tumors. It would be highly desirable if the drug release can be programmed so that the exact desired doses can be applied directly at a time at a specific location in the GI tract (e.g., on or near a tumor). Accordingly there is a need for a system to direct the movement and orientation of diagnosis and treatment vehicles within animal bodies.
This invention discloses such a convenient navigation system and navigatable capsules which are useful for remote-controlled imaging, biopsy and programmable drug release within the body of an animal. The components of the system comprise a capsule dimensioned and shaped to move within the body. An anisotropic magnetic component is mechanically coupled to the capsule to move or orient the body in relation to an applied magnetic field, and a magnetic field generating system external of the body generates a three dimensionally oriented magnetic field within the body to move or orient capsule.